Catalysis imprinted metal oxides

With the addition of a catalytic centre, an imprinted recognition site can be transformed into an enzyme mimetic material offering substrate selective catalysis. Over the past decade a few research groups have studied catalytic effects of imprinted metal oxides in esterification reactions. In this section a brief overview will be given on their efforts to understand the catalytic selectivity and structure of the active site. For additional reading an excellent review can be found by Davis et al. [46]. 

The first use of imprinted metal oxides for catalysis was performed by Morihara et al. in the late 1980s [47,48]. Substrate selective catalytic sites for the esterification of anhydrides were prepared using an alumina sol-gel technique formed on silica gel. Template molecules, present during the final stages of alumina gel formation, are thought to leave footprint-like impressions on the gel surface after subsequent... 

In addition to mesostructured metal oxide molecular sieves prepared through supramolecular assembly pathways, clays, carbon molecular sieves, porous polymers, sol-gel and imprinted materials, as well as self-assembled organic and other zeolite-like materials, have captured the attention of materials researchers around the globe. Clays, zeolites and sol-gel materials are still very popular because of their extensive and expanding applications in catalysis and separation science. Novel carbons and polymers of ordered porous structures have been synthesized. There are almost unlimited opportunities in the synthesis of new organic materials of desired structural and surface properties via self-assembly or imprinting procedures. 

This chapter focuses on several recent topics of novel catalyst design with metal complexes on oxide surfaces for selective catalysis, such as stQbene epoxidation, asymmetric BINOL synthesis, shape-selective aUcene hydrogenation and selective benzene-to-phenol synthesis, which have been achieved by novel strategies for the creation of active structures at oxide surfaces such as surface isolation and creation of unsaturated Ru complexes, chiral self-dimerization of supported V complexes, molecular imprinting of supported Rh complexes, and in situ synthesis of Re clusters in zeolite pores (Figure 10.1). 

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